diff -r 9f0b95aafaa3 -r ed84c8bdd87b src/org/sonews/daemon/CommandSelector.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/sonews/daemon/CommandSelector.java Sun Aug 29 17:28:58 2010 +0200 @@ -0,0 +1,141 @@ +/* + * SONEWS News Server + * see AUTHORS for the list of contributors + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +package org.sonews.daemon; + +import java.util.HashMap; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import org.sonews.daemon.command.Command; +import org.sonews.daemon.command.UnsupportedCommand; +import org.sonews.util.Log; +import org.sonews.util.io.Resource; + +/** + * Selects the correct command processing class. + * @author Christian Lins + * @since sonews/1.0 + */ +public class CommandSelector +{ + + private static Map instances + = new ConcurrentHashMap(); + private static Map> commandClassesMapping + = new ConcurrentHashMap>(); + + static + { + String[] classes = Resource.getAsString("helpers/commands.list", true).split("\n"); + for(String className : classes) + { + if(className.charAt(0) == '#') + { + // Skip comments + continue; + } + + try + { + addCommandHandler(className); + } + catch(ClassNotFoundException ex) + { + Log.get().warning("Could not load command class: " + ex); + } + catch(InstantiationException ex) + { + Log.get().severe("Could not instantiate command class: " + ex); + } + catch(IllegalAccessException ex) + { + Log.get().severe("Could not access command class: " + ex); + } + } + } + + public static void addCommandHandler(String className) + throws ClassNotFoundException, InstantiationException, IllegalAccessException + { + Class clazz = Class.forName(className); + Command cmd = (Command)clazz.newInstance(); + String[] cmdStrs = cmd.getSupportedCommandStrings(); + for (String cmdStr : cmdStrs) + { + commandClassesMapping.put(cmdStr, clazz); + } + } + + public static Set getCommandNames() + { + return commandClassesMapping.keySet(); + } + + public static CommandSelector getInstance() + { + CommandSelector csel = instances.get(Thread.currentThread()); + if(csel == null) + { + csel = new CommandSelector(); + instances.put(Thread.currentThread(), csel); + } + return csel; + } + + private Map commandMapping = new HashMap(); + private Command unsupportedCmd = new UnsupportedCommand(); + + private CommandSelector() + {} + + public Command get(String commandName) + { + try + { + commandName = commandName.toUpperCase(); + Command cmd = this.commandMapping.get(commandName); + + if(cmd == null) + { + Class clazz = commandClassesMapping.get(commandName); + if(clazz == null) + { + cmd = this.unsupportedCmd; + } + else + { + cmd = (Command)clazz.newInstance(); + this.commandMapping.put(commandName, cmd); + } + } + else if(cmd.isStateful()) + { + cmd = cmd.getClass().newInstance(); + } + + return cmd; + } + catch(Exception ex) + { + ex.printStackTrace(); + return this.unsupportedCmd; + } + } + +}